Wire-gripper

ABSTRACT

Apparatus for gripping an article such as a rod, wire or the like for drawing the article including a housing with a longitudinal slot extended upwardly by sidewalls defining a cavity in which a gripping member is pivotally mounted. The gripping member has an arm extending beyond the housing forming a part of a linkage with a second arm which extends through a slot in the rear of the housing adapted to slidably receive the second arm. The drawing force is applied to the second arm, which rotates the gripping member into contact with the article to be drawn.

United States Patent Primary Examiner- Richard A. Schacher Attorneys-Richard A. Speer, Vincent G. Gioia and Howard R. Berkenstock, Jr.

ABSTRACT: Apparatus for gripping an article such as a rod, wire or the like for drawing the article including a housing with a longitudinal slot extended upwardly by sidewalls defining a cavity in which a gripping member is pivotally mounted. The gripping member has an arm extending beyond the housing forming a part of a linkage with a second arm which extends through a slot in the rear of the housing adapted to slidably receive the second arm. The drawing force is applied to the second arm, which rotates the gripping member into contact with the article to be drawn.

PATENTEUJULZYIBYI 3595458 DONALD J. NOJA/M a STEFAN RIGL A Horney [NI/EN TORS.

WIRE-GRIPPER BACKGROUND OF THE INVENTION In the drawing of articles such as rods, wire, and the like through dies, several types of gripping apparatus are conventionally utilized. One type utilizes a wedge principal wherein a wedging device is forced into a chuck which contains also the article. Another type utilizes an arrangement of jaws which places holding pressure on the wire bythe closing of the .jaws. In the drawing of a rod, wire, or the like, inadvertent slippage or jerking of the article, as the drawing operation is started or during the drawing operation, imposes severe stresses upon the die and the gripping apparatus and damage thereto often results. Further, such slippage or jerking causes deformation or marring of the surface of the drawn product in the die during the interruption. With the known types of wire pullers; i.e., the wedge type and the jaw type, misalignment of the gripping mechanism is a common problem which also may be a principal cause of slippage and jerking of the drawn product. Further, the wedgeand jaw-type gripping mechanisms allow no resiliency at the initiation of a pull of the article through the die to cushion the shock of the commencement of the drawing operation.

SUMMARY OF THE INVENTION The gripping mechanism of our invention includes a housing in which an eccentric gripping member is pivotally mounted, which member contains a gripping surface, preferably serrated, which passes freely over a longitudinal slot in the bottom of the housing. The rod, wire, or the like to be drawn is inserted into the housing into the slot whereupon the gripping member is rotated downward to engage the article by the gripping surface. Projecting from the gripping member is an arm passing through an opening in the housing, the gripping member and 'arm closely fitting in the housing. The close-fitting relation of the member in the housing minimizes lateral movement of the member and the gripping surface which insures alignment of the surface with the rod, wire, and the like within the slot. The drawing source is transmitted through the first arm by a connecting arm in the preferred embodiment in such a manner to increase the engaging force on the article in the machined slot to minimize any possibility of further slippage during the draw. Further, the rotation of the gripping member by the drawing force allows some slight resiliency in the engagement of the rod, wire, or the like as the draw is commenced to eliminate jerking of the wire or rod in the die when the drawing is initiated. Damage to the dies as well as damage to the drawn product is also reduced by reducing slipping and jerking of the article.

DESCRIPTION OF THE DRAWINGS i The FIGURE illustrates, by pictorial view, the gripping apparatus of our invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the FIGURE, reference numeral 2 indicates a wire-gripping mechanism to assist in the drawing of an article W such as a rod, wire, or the like. Gripper 2 has a housing 4 which has a longitudinal groove 6 extending therethrough generally parallelly aligned within the direction of force D for drawing the article W. Within housing 4, Iongitudinal groove 6 is defined by sidewalls 8 forming an opening 10 in which gripping member 112 is mounted. In the,

crease the gripping capacity of surface 14. Extending from -gripping member 12 is arm 20 protruding above housing 4 out of opening '10. Pivotally attached to arm 12 is a connecting arm 22 to which the drawing force D may be applied.

In preferred arrangement, housing 4 has a built-up portion 24 having an opening 26 extending therethrough substantially in line with drawing force D. Opening 26 is adapted to closely and slidably'receive connecting arm 22 such that any lateral forces developed in the drawing operation are transmitted to housing 4 within the area of longitudinal opening 26 and not concentrated in the area where gripping surface 14 contacts article W.

In operation, article W is inserted into slot 6 by rotating arm 20 and gripping member 12 in a clockwise direction, as illustrated in the drawing. Article W is preferably inserted sufficiently far within the slot 6 such that a substantial portion of gripping surface 14 engages it as the gripping member is rotated counterclockwise. Gripping surface 14 contacts article W due to the eccentric nature of the gripping surface 14 relative to pivotal mounting 13. Thus, increasing the counterclockwise rotation as illustrated in the FIGURE increases the pressure with which the surface 14 presses article W into slot 6. Rotational movement is provided to gripping member 12 through connecting arm 22 pivotally attached at 21 to arm 20 extending from gripping member 12. A drawing force D applied such as through chain to connecting arm 22 provides the drawing force and the resulting counterclockwise movement in gripping member 12. It is to be noted that as the drawing operation is commenced, the drawing force operating through connecting arm 22 and arm 20 will cause some slight counterclockwise movement allowing surface 14 to rotate about pin 13. This slight movement at the commencement of the drawing operation allows article W to move slightly to cushion the shock of the beginning of the draw. It will be further noted that, as the drawing forces increase, the drawing force operates through connecting arm 22 and arm 20 to increase the holding force on article W through surface 14 thus protecting and minimizing any slippage of wire due to an instantaneously increased drawing force. It will also be noted that the gripping member closely cooperates with sidewalls 8 in the area ofthe gripping member 12 and connecting arm 22 closely cooperates with opening 26. The net effect of the close cooperation of the aforementioned members is to minimize, if

not eliminate, lateral movement of the surface 14 with respect to article W during the drawing operation. This elimination of lateral movement enhances the ability of surface 14 to hold article W without slippagewhich might be initiated by sudden lateral movement of the gripping surface. Further, it maximizes the holddown force existing between surface 14, article W and slot 6 by concentrating the holding forces in the plane of the slot article W and gripping member 12, rather than at different angles.

The gripping capacity of the apparatus 2 may be further enhanced by configuring the surface 14 and slot 6 to the general cross-sectional configuration of the article W. In the instance of wire, the slot 6 and surface 14 may be made concave to maximize the contact with the article W.

While several embodiments of our invention have been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the appended claims.

We claim:

1. Apparatus for gripping an elongated article such as a rod, wire, or the like for drawing same, comprising: a housing having a longitudinal groove running therethrough capable of receiving said article; sidewalls defining said groove and extending parallelly out of said groove to form a cavity; a gripping member within said cavity between said sidewalls communicating with said groove eccentrically and rotatably mounted to said sidewalls such that rotation of said member will cause said member to press and grip an article disposed in said groove; a connecting arm pivotally attached to said gripping member, means for transmitting a drawing force to therefrom, pivotally mounted in said sidewalls and pivotally attached to said connecting arm, said member having a serrated surface to grip said rod, wire, or the like.

4. Apparatus according to claim 1, wherein said gripping member contains a removable insert having a gripping surface.

5. Apparatus according to claim 1 wherein said gripping surface and longitudinal slot are configured to the general cross-sectional configuration of the article to be gripped. 

1. Apparatus for gripping an elongated article such as a rod, wire, or the like for drawing same, comprising: a housing having a longitudinal groove running therethrough capable of receiving said article; sidewalls defining said groove and extending parallelly out of said groove to form a cavity; a gripping member within said cavity between said sidewalls communicating with said groove eccentrically and rotatably mounted to said sidewalls such that rotation of said member will cause said member to press and grip an article disposed in said groove; a connecting arm pivotally attached to said gripping member, means for transmitting a drawing force to said connecting arm, said housing having a built-up portion aligned with the plane of said gripping member, and alignment means within said housing''s built-up portion operable with said connecting arm to minimize lateral forces in said gripping member.
 2. Apparatus according to claim 1 wherein said alignment means is a slot running through said housing and said connecting arm is closely and slidably received in said slot.
 3. Apparatus according to claim 1 wherein said gripping member is an eccentric cam having an arm extending therefrom, pivotally mounted in said sidewalls and pivotally attached to said connecting arm, said member having a serrated surface to grip said rod, wire, or the like.
 4. Apparatus according to claim 1, wherein said gripping member contains a removable insert having a gripping surface.
 5. Apparatus according to claim 1 wherein said gripping surface and longitudinal slot are configured to the general cross-sectional configuration of the article to be gripped. 